Vat dyestuffs of the anthraquinone series and a process of preparing them



Patented Feb. 2, 1937 UNITED STATES PATENT VAT DYESTUFFS OF THE ANTHRAQUINQNE .SEERIES AND A PROCESS OF PREPARING HEM No Drawing. Application March 23, 1933, Serial No. 662,392. In Germany March 26, 1932 OFFICE 8 Claims.

The present invention relates to vat dyestuffs of the anthraquinone series and to a process of preparing them, more particularly it relates to ing a caustic alkali melt to act at an elevated temperature, such as about 230 to 270 C., upon a compound of the group consisting of 4-anthracompounds of the following formulae:

quinonylaminonaphthalene-1.8-dicarboxy1ic acid imides and 4-anthraquinonylamino-1.8-naphtho- 5 ylenearylimidazoles, aryl meaning an aryl group of the benzene series. The vat dyestuffs obtainable from the said naphthalimides probably correspond to the Formula I above given in which aryl may be substituted by any other radical.

The vat dyestuffs obtainable from the said naphthoylene-arylimidazoles probably correspond to the Formulas II and III above given. In many cases the dyestuffs are obtained as mixtures of isomeric compounds which may be separated into their components.

According to the present process a great number of new products are obtainable, for instance, those of the following general formula:

(II) V wherein R1 and R2 jointly represent a bivalent and We have found that valuable vat dyestuffs of the anthraquinone series are vobtainable by causwherein R3 represents an alkyl or an aryl group of the benzene series and R4 represents an aryl group of the benzene series, which is bound in two adjacent positions to the nitrogen atoms.

The following examples serve to illustrate the invention but they'are not intended to limit it thereto, the partsbeing by weight:

(1) 27.7 parts of 4-bromnaphthalic acid anhydride are condensed in the usual manner in 300 parts of nitrobenzene with 23 parts of a-aminoanthraquinone. The body thus obtained crystallizes from chlornaphthalene in'the form of red-brown crystals and melts at about 400 C.

g It dissolves in concentratedgsulfuric acid to an olive-green solution. 10 parts of the reaction product are heated with parts of orthophenylenediamine to 230 0., whereby the melt 1 solidifies with elimination of the new product which, likewise, forms red-brown crystals and 'meltsat about 373 C. In concentratedsulfuric acid the substance "dissolves to a red solution.

The condensation product thus obtainable 'is melted in 10 times its weight of caustic potash. At 230 C. to 240 C. the. reaction product separates from the melt. The dyestuif is firstobtained in the form of the leuco compound and is best oxidized by means of air. After purification and recrystallization from organic solvents a green dyestufi is obtained which dyes cotton from V red-Violet vat aft xpo ure to' air, a beautiful green shade. I

(2) The condensation product from 4-bromo- 1.8-naphthalene-dicarboxylic acid anhydride and a aminoanthraquinone is boiled with 5 times its weight of aniline. There'is obtained a red-brown condensation product which dissolves in sulfuric acid to a red isolution. The. product thus obtainable is melted with 10 times its. weight of V caustic potash and a trace of alcohol. .At 230C.

the ;dyestufi V separates from the melt. It is worked up as described in Example 1. .It dyes cotton from a red vat bluish-green tints.

furic acid to a red solution.

(3) 14 parts of l-bromo-naphthalic acid 'anhydride. are boiled with 5.4 parts of orthoephe- 'nylenediamine for 4 hours in glacial acetic acid. During the boiling; bromo--1'-8'-naphthoylenebenzimidazole separates in the form of small yellow flakes. It melts at about 241 C.+243 C. and

dissolves in sulfuric' acid'to a yellow solution.

The yieldamountsjto about of that of the theory. 10.5 partsof the benzimidazole of naphthalic acid thus obtained arecondensed in'the usual manner with 7 parts of a-aminoanthraquinone in nitrobenzene and-there is obtained with a very good yield-a condensation product melting at367 Cr-368 C. and dissolving insullpart of the condensation product thus obtainable is iheltedwith I 10 parts of causticpotashfi The formationof the dyestuff takes place at 230 C. to 240 C. The product is worked up as described in Example 1. The same green dyestufi is obtained.

(4) By crystallization from chlorobenzene, the intermediate productobtainable according to Example 3, i. e. bromo-1'8-naphthoylene-benzimidazole,'may be separated into two isomeric components, one of which melts at 223 C. and is rather easily soluble in chlorobenzene and the other is more difficultly soluble in chlorobenzene and melts at 283" C.

(a) The compound melting at 223 C..is condensed as indicated'in Example 3 with alphaaminoanthraquinone. There is obtained a redbrown crystalline compound melting at about product of fusion'dyes' cotton from a red-violet 1 vat dull greentihts;

380C. and dissolving in concentrated sulfuric acid to a red solution- The condensation product thus obtainable is introduced by C. into a melt of 10 parts of caustic potash and 1 part of alcohol, the temperature is raised to 250 C. and the wholeis kept molten for 50 minutes at 250 C. to 260 C. A green dyestufi is obtained yielding a red-violet vat. From nitrobenzene the dyestufi' crystallizes in, the form of needles melt- V a "10 a (b) Fr 0 m bromnaphthoylenebenzimidazole melting at 283 C. there is obtained. in the maning at 342 C. to 343 C.

ner indicated in Example 3, by means of alphaaminoanthraquinone a red-brown crystalline product which melts at about 400 C. and dissolves in concentrated sulfuric acid to a red' solution. Bymelting the compound thus obtainable as indicated under 4 (a), a. yellowish-green dyestufi is obtained which yields a violet vat andcrystallizes from nitrobenzene in the form of needles melting at 363 C r Probably the dyestufi melting at 342 C.-343

C. as described in Example 4 (a) has the constitution of Formula IV and the dyestufi melting at 363 C. as described in Example 4 (b) is supposed to correspond with the constitution or Formula V.

(5), 14 parts of 4-bromo-naphthalic acid anhydride are heated to boiling for 1 hour with 7.5 parts of para-'chloro-ortho-phenylenedlamlne in 100 parts of glacial: acetlcacid, the whole is fil-' tered with suction while hot, the solid. matter is washed with alcohol a nd. if desired, extracted by boiling with dilute caustic soda solution. 4"-

bromo-1 -8'-naphthoylene -chloro 4 benzimidazole' formsa yellow crystalline product melting at 230 0.

23.4 parts r ben'zir'nidazole,,2 2.3 parts or alphaaminoanthraquinone, l0 parts of potassium-acetate,-2 parts of cuprousiodide and 400 parts of nitrobenzene are .heatedto boiling for 5 hours." The Wholeisifilteredwith suction at 100 'C., the. solid matter iswashedwith nitrobenzene, alcohol and water and dried. The condensation product which crystallizes in brown needles is obtained with a good yield.

10 parts of the. condensation product thus obtainable are introduced at 100 C.,into a mixture of parts of caustic potash and 15 parts of alcohol and the temperature is slowly raised to 250 C.-260. 'C. After-.Iiminutes, the melt is mixed with water, air is"blown in, the whole is filtered with suction and the solid matter is washed untilneutral and dried. The dark green 6) 14 parts of 4bromo-'naphthalic acid anhydride, 9 parts ofthehydrochloride of ortho-ortho'- diamino-benzidine, 10 parts of sodium acetate and 200 parts of glacial acetic acid are heated to boiling for 1 hour. The Whole is filtered with suction, while hot, and the solid matter is washed with alcohol. The di-(4-bromo-l-8'-naphthoylene-benzimidazole) forms a red-brown powder melting above 360 C.

7 parts of said di-b'enzimidazole, 4.5 parts of alpha-amino-anthraquinone, 2 parts of potassium acetate and 0.4 part of cuprous iodide are heated to boiling for 5 hours in parts of nitrobenzene. At C. the whole is filtered with suction and the solid matter is washed with nitrobenzene, alcohol and water. Thedark brown Econdensation product is obtained with'a good yield.

10 parts of the condensation product thus obtainableare introduced at 100 C. into a mixture of 150' parts of caustic potash and 15pa'r'ts0f 'alcohol. The whole is then slowly heated to 260C. to 270 C. and this temperature is maintained for 1 hour. in Example 5. from a red-violet vat yellowish-green tints.

(7) By using in Example 2 instead of aniline, monome thylamine and by working under the same conditions with an alcoholic caustic potash melt, there is obtained a dyestufi which dyes from a violet vat intense grey-olive tints.

We claim:

1. The process which comprises causing a caustic alkali melt to act at a temperature of about 230 C. to about 270 C. upon a 4 anthraquinonylamino- 1,8-naphthoylenearylimidazole, aryl meaning an aryl group of the benzene series.

2. The process which comprises causing a caustic potash melt to act at a temperature of about 230 C. to about 240 C. upon a mixture of isomeric compounds of the following formulae:

3. The process which comprises causing a caustic potash melt to act, in the presence of alcohol, at a temperature of about 250 C. to 260 C. upon a compound of the following formula:

4. The process which comprises causing a The product is worked up as described The dyestufi obtained dyes cotton I caustic potash melt to act; in the presence of. alcohol, at a temperature of about 250 C. ;to about 260 C. upon a compound of the following formula;

' 5. The products 5% the following formula:

wherein R1 and R2 jointly represent a bivalent radical of the formula wherein R3 represents an aryl group of the benzene series, which is bound in two adjacent positions to the nitrogen atoms, said products being vat dyestuffs dyeing the fiber greenish tints.

6. The mixture of the products of the following formulae:

being a green'dyesttifl anddyeing cotton from a.

red-violet vat, after'exposure to air, a. beautiful green tint.

7. The product of the following formula? Y being a green dyestufi which yields red-violet at and crystallizing from nitrobenzene in the form of needles which melt at 342 C. to 343 C.

" 2,069,663 I V r e v 8. The product of the following formula:

being a yellowishgreen dyestufi which yields'd. violet vat and crystalllzing from nitrobenzene in the form'of needles melting at 363 C.

7 ARTHUR WOLFRAM;

PAUL NAWIASKY. e GERHARD LANGBEIN. WERNER ELBS. v r 

